automatically fetch replacement previews for selected search results

zanata-war/src/main/java/org/zanata/webtrans/client/presenter/SearchResultsPresenter.java

@@ -200,6 +200,8 @@ HasData<TransUnitReplaceInfo> addDocument(
 
    private Map<Long, String> docPaths;
 
+   private boolean autoPreview = true;
+
    @Inject
    public SearchResultsPresenter(Display display, EventBus eventBus,
          CachingDispatchAsync dispatcher,
@@ -317,12 +319,7 @@ public void onChange(ChangeEvent event)
          @Override
          public void onClick(ClickEvent event)
          {
-            List<TransUnitReplaceInfo> selected = new ArrayList<TransUnitReplaceInfo>();
-            for (MultiSelectionModel<TransUnitReplaceInfo> sel : documentSelectionModels.values())
-            {
-               selected.addAll(sel.getSelectedSet());
-            }
-            firePreviewEvent(selected);
+            previewSelected(false, false);
          }
       }));
 
@@ -607,6 +604,11 @@ public void onSelectionChange(SelectionChangeEvent event)
          {
             int selectedFlows = countSelectedFlows();
 
+            if (autoPreview)
+            {
+               previewSelected(true, true);
+            }
+
             if (selectedFlows == 0)
             {
                setUiForNothingSelected();
@@ -621,6 +623,36 @@ public void onSelectionChange(SelectionChangeEvent event)
       };
    }
 
+   /**
+    * 
+    * @param skipEmptyNotification true to silently ignore the request when no rows are selected
+    */
+   private void previewSelected(boolean skipEmptyNotification, boolean hideNonSelectedPreviews)
+   {
+      List<TransUnitReplaceInfo> selected = new ArrayList<TransUnitReplaceInfo>();
+      for (MultiSelectionModel<TransUnitReplaceInfo> model : documentSelectionModels.values())
+      {
+         selected.addAll(model.getSelectedSet());
+      }
+
+      if (!skipEmptyNotification || !selected.isEmpty())
+      {
+         firePreviewEvent(selected);
+      }
+
+      if (hideNonSelectedPreviews)
+      {
+         for (TransUnitReplaceInfo info : allReplaceInfos.values())
+         {
+            if (info.getPreviewState() == PreviewState.Show && !selected.contains(info))
+            {
+               info.setPreviewState(PreviewState.Hide);
+            }
+         }
+      }
+   }
+
+
    /**
     * Fire a {@link PreviewReplaceText} event for the given {@link TransUnit}s
     * using parameters from the current history state. This will also update the
@@ -637,6 +669,13 @@ private void firePreviewEvent(List<TransUnitReplaceInfo> toPreview)
          eventBus.fireEvent(new NotificationEvent(Severity.Warning, messages.noTextFlowsSelected()));
          return;
       }
+      final String replacement = currentHistoryState.getProjectSearchReplacement();
+      // prevent failed requests for empty replacement
+      if (replacement.isEmpty())
+      {
+         eventBus.fireEvent(new NotificationEvent(Severity.Warning, messages.noReplacementPhraseEntered()));
+         return;
+      }
 
       List<TransUnit> transUnits = new ArrayList<TransUnit>();
       for (TransUnitReplaceInfo replaceInfo : toPreview)
@@ -662,7 +701,6 @@ private void firePreviewEvent(List<TransUnitReplaceInfo> toPreview)
       }
 
       final String searchText = currentHistoryState.getProjectSearchText();
-      final String replacement = currentHistoryState.getProjectSearchReplacement();
       boolean caseSensitive = currentHistoryState.getProjectSearchCaseSensitive();
       ReplaceText action = new ReplaceText(transUnits, searchText, replacement, caseSensitive);
       PreviewReplaceText previewAction = new PreviewReplaceText(action);
@@ -1054,7 +1092,8 @@ private void processHistoryToken(HistoryToken token)
          }
       }
 
-      if (!token.getProjectSearchReplacement().equals(currentHistoryState.getProjectSearchReplacement()))
+      boolean replacementTextChanged = !token.getProjectSearchReplacement().equals(currentHistoryState.getProjectSearchReplacement());
+      if (replacementTextChanged)
       {
          display.getReplacementTextBox().setValue(token.getProjectSearchReplacement(), true);
          for (TransUnitReplaceInfo info : allReplaceInfos.values())
@@ -1067,6 +1106,12 @@ private void processHistoryToken(HistoryToken token)
       }
 
       currentHistoryState = token;
+
+      // uses currentHistoryState so must execute after token is updated.
+      if (replacementTextChanged && autoPreview)
+      {
+         previewSelected(true, false);
+      }
    }
 
    /**

zanata-war/src/main/java/org/zanata/webtrans/client/resources/WebTransMessages.java

@@ -205,6 +205,9 @@ public interface WebTransMessages extends Messages
    @DefaultMessage("Replace text failed")
    String replaceTextFailure();
 
+   @DefaultMessage("No replacement text has been entered")
+   String noReplacementPhraseEntered();
+
    @DefaultMessage("No replacements to make")
    String noReplacementsToMake();